Fastener driving tool and release therefor



July 26, 1960 E. POWERS ETAL 2,946,313

' FASTENER 0 m TOOL AND RELEASE THEREFOR Filed Feb. 3, 1958 2Sheets-Sheet 1 INVENTOR. P/Cf/ARD 5 Po WERE BY CAM/HES M WE/S AQsA/rJuly 26, 1960 R. E. POWERS ETA!- 2,946,313

FASTENER DRIVING TOOL AND RELEASE THEREFOR Filed Feb. s, 1958 2Sheets-Sheet 2 FIG. 4

FIG. 6.

INVENTOR.

Y RICHARD E POWERS CHARLES M h/E/s A GENT United States Ptent a)FASTENER DRIVING TOOL AND RELEASE THEREFOR Richard E. Powers, MontereyPark, and Charles W.

Weis, Arcadia, Calif., assignors to Powers Wire Products Company, Inc.,Monterey Park, Califi, a corporation of California Filed Feb. '3, 1958,Ser. No. 712,977

13 Claims. (Cl. 121-13) This invention is concerned with a fluidoperated device or drive and particularly relates to a release for acylinder and piston drive means for use in fastener driving tools, andthe like, it being a general object of this invention to provide areliable and commercially practical release for tools of the type underconsideration wherein substantial driving force or impact is required.

Fluid actuated motors are used to operate fastener dr-iving tools, forexample stapling guns and the like. These tools require a substantialdriving force in one direction accompanied by quickness of action, andin order to accomplish this result it is common practice to employ alatching means adapted to hold the driving piston in a retractedposition until pressure is developed in the cyl in der, after which thesaid piston is released. By releasing the piston after pressure hasbuilt up in the cylinder it is possible to obtain the quickness ofaction desired and which results in the required force and impact at theend factory since they become misaligned and jammed, and 1 because thenumber of rollers that may be used is limited, usually to two rollersonly. In other words, latching means involving rollers are not alwaysreliable.

An object of this invention is to provide a fastener driving tool andlatching means therefor that provides a reliable locking and releasingaction. The latching means that we provide involves balls that areshiftable radially in a predetermined manner to engage and disengagewith a head projecting from the piston.

It is an object of this invention to provide a latching means in afastener driving tool wherein the head projecting from the piston isoperated upon by a multiplicity of elements to be engaged and disengagedthereby. With the latching means that we provide a multiplicity ofcontacts are provided by employing a series of circumferentiallydisposed balls that move radially in a predetermined manner.

It is still another object of this invention to provide a latching meansin a tool of the type under consideration wherein the balls that areemployed are not only guided, but are also limited to a restrictedinward travel.-

It is still another object of this invention to provide a. latchingmeans in a tool of the type under consideration wherein the balls arefree to move radially outward to receive the head projecting from thepiston when the head moves into the latching position.

It is still another object of this invention to provide a latching meansin a tool of the type under consideration ,wherein the balls are movedradially inward to engage 2,946,313 Patented July 26, 1950 with the headand to be locked therewith when downward force is applied to the pistonby fluid pressure.

It is still another object of this invention to provide a latching meansin a tool of the type under consideration wherein the balls are releasedfrom the head by means responsive to fluid pressure developed in thecylinder to drive the piston through its work stroke.

Also, it is an object to provide a relatively simple and inexpensivelatching means of the character above referred to that is reliable inits operation and not subject to failures.

The various objects and features of our invention will be fullyunderstood from the following detailed description of a typicalpreferred form and application of our invention, throughout whichdescription reference is made to the accompanying drawings in which:

Fig. l is a side sectional view of a fastener driving tool thatincorporates the features of the present invention. Fig. 2 is anenlarged sectional view at the latching means that we provide, taken asindicated by line 22 on Fig. 1 and showing the parts thereof in a lockedposition. Fig.

,3 is a view similar to Fig. 2 and showing the parts thereof in areleased position. Figs. 4, 5 and 6 are detailed sectional views showingthe parts of the latching means in a latching position, a lockedposition and in a releasing position, respectively, Fig. 5 being a viewtaken as indicated by line 55 on Fig. 2, and Fig. 6 being a view takenas indicated by line 66 on Fig. 3. And, Fig. 7 is an enlarged detailedview of a portion of the mechanism illustrating the manner in which theinward movement of the locking means is restricted.

The latching means, or release mechanism, of the present invention isshown incorporated in a pneumatic or air operated tool, or fastenerdriving gun. The fastener driving tool and release therefor that we haveprovided may be in the form of a stapling gun and, therefore, in thedrawings we have illustrated this type of tool. It is to be understood,however, that the present invention :is not limited to this particularkind of tool and may be employed in connection with various tools havingcylinder and piston drive means, or the like.

The tool shown in Fig. 1 of the drawings is adapted to be handledmanually and involves, generally, a frame A having a body portion 10 anda handle or grip portion 11, a head B carried by the frame A and adaptedto direct fasteners into a piece of work, a magazine C for handling asupply of fasteners such as staples and cooperating with the head B sothat the staples are received and handled by the head, a driver blade D,a guide means E for handling the staples and accommodating the driverblade D so that it is continuously guided by the head B, latching meansF adapted to cooperate with and control operation of the driver blade D,a piston G having driving connection with the driver blade D, a dampingmeans H for the piston G, and a valve means I adapted to control thesupply of fluid under pressure to actuate the piston G and operate thelatching means F to release the piston.

The frame A carries the various elements of the tool, and is shaped tobe conveniently handled by a person. The frame A involves, generally,the body portion and the handle or grip portion 11. The body portion 10is a simple elongate part having a cylinder 12 extending longitudinallythereof and having an opening or passage 17 extending longitudinallythrough the lower head end thereof at one end of the cylinder 12, and ischaracterized by a flat front face 13 and a recess 14. The front face 13is at the forward end of the body and is normal to the longitudinal axisof the body, while the recess 14 is in the form of a fiat seat spacedlaterally of the axis of the body parallel therewith. The said seatextends rearwardly that is rectangular in cross sectionaleonfiguratiomopens to the exterior of the body. The shoulder 16 isnormal to the longitudinal axis of the body.

The handle or grip portion 11 is provided to give the. person handlingthe tool a convenient means to hold the tool, and it is a simple grip ofordinary construction that projects from the body 10. In practice, thegrip 11 may be substantially normal to the axis of the body and mayproject therefrom as clearly shown.

In structures of the type under consideration it is common practice toprovide a fluid pressure supply connection 18 at the grip 11, such as apneumatic hose or the like, and also to include a control means at thegrip 11. It is to be understood that any suitable fluid pressure supplycan be provided without affecting the present invention. When compressedair is employed, as in the case illustrated, the hose of the powerconnection 18 is attached to the grip 11 through a quick disconnect 20and the valve means I is under control of a finger operated trigger 21.

The head B is, in effect, an extension of the body of the frame A and isprovided to receive and deliver fasteners such as staples to the workbeing acted upon by the tool. The head B is carried by the body 10 inthe recess 14 and is provided with a longitudinal guideway 22 thatextends through and opens at the ends of the head B. The

head B has a. bottom face 23 engaged with the seat of recess 14, it hasa rear end face 24 normalto the axis thereof and engaged with theshoulder 16, and it has a front end face 25 engageable with the Work.

In the particular form of the invention shown, the guideway 22 isadapted to handle fasteners or staples S that are U-shaped and formed ofwire, or the like, having a pair of sharpened ends. The staples referredto are substantially elongate with straight parallel shanks joined by acurved back. It will be apparent how the guideway 22 can'be proportionedso that it will readily pass the staples with clearance and will actupon the staples to guide them as they are delivered through the head Band from the tool. The guideway 22 is a continuation of the passage .17above described and guides the driver blade of the tool as well as thestaples S that are handled thereby.

A fastener or staple receiving opening 32 extends laterally through thehead B, which opening enters the bottom face 23 of the head and opensinto the passage 22 so that the staples S fed to the head B are properlyguided and aligned with the passage 22 before they are engaged by thedriver blade D of the mechanism. The passage 22 has a staple guidingportion at the front of the head B of sufficient width to freely pass afastener or staple handled by the head B, and the passage 22 has a bladeguiding portion rearward of the first mentioned portion that is ofincreased width in order to accommodate the relatively large plunger ordriving blade D.

The magazine C is adapted to handle a supply or stack of fasteners orU-shaped staples S and involves, generally, a case 35 carried by theframe A, a guide 36 within the case 35, a follower 37 adapted to advancethe fasteners or staples, and a feed spring 38 yieldingly urging thefollower toward the head B. The case 35 is carried by the front face ofthe body 10 and is an elongate part that projects laterally from theframe A. The case is shelllike in form and the guide 36 is a core-likepart that is carried within and is coextensive with the case 35. Thecase 35 and guide 36 are shaped so that a longitudinal passage isformed, which passage conforms in general configuration to the U-shapedstaples S which are handled by the head B.

The guide 36 enters the fastener or staple receiving opening 32 andterminates in a flat end 39 that occurs in the plane of the bottom wallof the guideway 22. The follower 37 conforms with the configuration ofand is slideably carried in the passage in the guide 36 and isyieldingly urged toward the head B by the feed spring 38. Means isprovided to prevent the follower 37 from entering the guideway 22. Thefasteners or staples S are inserted into the magazine C through the opentop thereof the tool.

has sealing means, preferably an 0 ring type seal.

by simply engaging them over the guide 36 ahead of the follower 37tensioning the spring 38. As clearly shown, a spring biased latch 30secures the follower 37 in a retracted position when desired, thusfacilitating insertion of the fasteners.

The driver blade D is essentially a slender elongate part rectangular incross sectional configuration and terminates at its forward end in aflat fastener or staple driving face 45. The blade D has a stapledriving portion at the forward end thereof which occupies the stapleguiding portion of the guideway 22 when the driver is in the advancedposition (not shown), and also has a stern that is guided by the bladeguiding portion of the guideway 22. As shown, the blade D is providedwith an inclined earn or face 48 that is pitched upwardly and rearwardlyand which is provided to shift the guide means E.

The guide means E is in the form of a closure of gate 50 that ispivotally carried by the head B so that it normally substantiallyoccupies the top of the head B. As shown, the gate 50 is elongate and isshiftably carried by the head B by means of a pivot pin 51. A spring 52is provided to yieldingly hold the gate 50 in a down or normal positionWhere it forms a continuation of the guideway 22 and thereby guides thestaples handled by the tool and also guides the driver blade D of thetool. A head construction for a fastener driver of the type referred tois particularly 'set forth and claimed in Letters Patent No. 2,784,406issued to Richard E. Powers March 12, 1957.

The latching means F that we have provided in accordance with thepresent invention is adapted to cooperate with and control operation ofthe piston G. The means F is is provided to couple with and to hold thepiston G at the upper end of the cylinder 12 and to release the piston Gwhen sufiicient fluid pressure has been established in the cylinder toeffect the desired work stroke of For this purpose a latching stem 53projects from the top of the piston G, and is shaped to be engaged anddisengaged by the latching means F. The piston G is slideahly operablein the cylinder 12 and is actuated by fluid pressure to advance in thecylinder '12 in a manner common to tools of the type underconsideration. The piston G is suitably coupled to the driver blade Dand In order to retract'the' piston G there is provided a return spring54 acting under compression between the lower end .of the cylinder 12and the bottom of the piston G.

The latching stem 53 that is provided to be held by that projectsupwardly from the top of the piston G on with the latching means F andinvolves an annular recess or channel 55. The channel 55 is formed inthe outer peripheral wall of the stem and it is arcuate in crosssectional configuration in order to have seating engagement with thelocking balls hereinafter referred to. In practice, the depth of thechannel 55 is equal to approximately one quarter the diameter of saidballs (as shown). In carrying out the invention, the upper wall of thechannel 55 is tapered upwardly and outwardly to the end that theterminal end portion of the stem is in the form of an inverted cone (seeFigs. 4, 5 and 6). Further, the top of the head or stem 53 is fiat in aplane normal to the axis thereof, and is chamfered at the periphery 56,preferably at a 45 angle. The shape of the head or stem facilitates thefunction of latching, locking and release, as hereinafter set forth.

The latching means F is provided to cooperatively engage with thelatching stem 53, above referred to, and is adapted to latch onto thestem 53, to lock itv in a fixed position, and torelease it when apredetermined fluid pressure is developed within the cylinder 12. Asbest illustrated in Figs. 4, 5 and 6 of the drawings,the latching meansF involves, generally, an anchor X, lock. balls L,

upward travel of the sleeve Y. invention, the sleeve Y has a recess 73formed in the a release sleeve Y, and a pressure responsive means Z. Theanchor X adjustably positions the elements of the latching means inorder to obtain the desired releasing action, and it is formed to guidethe lock balls L for proper functioning. The lock balls L move or shiftradially inward and outward to be engaged with and disengaged from thelatching stem 53. The sleeve controls radial movement of the balls L,and the pressure responsive means Z actuates the sleeve Y in response tofluid pressure within the cylinder 12.

The anchor X, that adjustably positions the elements of the latchingmeans F and which guides the balls L, is a straight elongate part thatis carried by the cylinder head 12' to depend into the cylinder 12 onthe central axis thereof. The anchor X is shiftable axially of thecylinder 12 and for securing the desired adjustment it has a theadedstem 60 threadedly carried in the head 12' and secured in the selectedposition by means of a lock nut 61. The lower end portion of the anchorX is in the form of a head 62 having a turned exterior wall 63 slidablycarrying the sleeve Y and having a central bore 64-slidably receivingthe top terminal end portion of the latching stem 53. The head 62 islarger in diameter than the stem 60 presenting an upwardly facing end 65that forms a stop for the means Z later described. The exterior wall 63of the head is stepped at 66 to form an upwardly facing shoulder 67 (asshown).

As clearly illustrated in the drawings, the head 62 is formed to carryand guide the lock balls L and has there-- for a plurality of guideopenings 68 formed therein, for example we have shown four such openings68. The

openings 68 are elongate vertically disposed slot-shaped openingsslightly wider than the diameter of the balls L, so that the balls arefree to move radially and vertically in the openings. The openings 68extend through the Wall of the head 62 between the exterior wall 63and'bore 64, the thickness of said wall (in the case illustrated) beingapproximately 75% of the diameter of the balls L.

In accordance with the invention, and as illustrated in Fig. 7 of thedrawings, the openings 68 are formed so v.one ball L operating in eachopening 68. Further, the top of the opening 68 is pitched while thebottom is not, the top being pitched at, for example, 20. we employ atapered cutter to form the openings 68, the

In practice,

axis of rotation of the cutter being pitched or inclined to establishthe horizontal bottoms and substantially inclined tops, as shown.

The release sleeve Y that controls radial movement of the balls L isshiftable axially relative to the head 62 and is engaged over the head.The sleeve Y has a bore 70 slideably engaged with the wall 63 of thehead, an outwardly projecting radial flange 71 at the upper end thereofand an inwardly projecting radial flange 72 at the lower end thereof.The flange 71 is provided to engage with the pressure responsive means Zto be actuated thereby, while the flange 72 is pro'vided to limit Inaccordance with the bore 70 at or near the lower end portion of thesleeve. The recess 73 is a continuous annular recess that is normallypositioned below the series of openings 68, for example when the sleeveis in a down position as shown in Figs. 4 and 5. When the sleeve is insaid down position the upper portion of the bore 70 surrounds the lowerportion of the slot-shaped openings 68 to prevent outward radialmovement of the balls L (see Fig. As

; shown, the upper end of the bore 70 is chamfered at 74,

preferably at 45, and the side walls of the annular recess 73 are alsopitched at 45. When the sleeve is in an up position, as shown in Fig. 6,the annular recess 73 is opposite the lower end portions of the openings68 and outer spherical portions so that the balls L are received in therecess 73 and so that the inner spherical portio'ns of the balls L arewithdrawn from the bore 64 and latching stem 53 (see Fig. 3).

The pressure responsive means Z that actuates the sleeve Y is responsiveto fluid pressure in the cylinder 12 and is in the form of a piston andis provided to engage with and shift the sleeve Y to release the balls Lwhen a predetermined fluid pressure is developed within the cylinder 12.In the particular case illustrated, the piston body of the means Z iscarried over and surrounds the above described elements of the means F.The body 80 is an inverted cup-shaped part slidably engaged with thestem 60 and sealed off therefrom by means of an O ring seal. Adownwardly facing seat 81 is formed on the body 80 to have stoppingengagement with the top end 65 of the head 62 when the means Z is in anormally unactuated position (see Figs. 4 and 5). The body 80 is formedwith a of a packing, for example an O ring seal. The spring 84 actsunder compression between the cylinder head 12 and the top of the body80 to the end that said spring is compressed when fluid under pressureis introduced into the cylinder between the piston G and piston body 80causes lifting of the sleeve Y and consequent release of the balls L.

A counterbore is provided in the piston body 80 to accommodate biasingmeans that yieldingly urges the balls L downwardly. In practice weemploy a compression spring 91 that urges a washer 92 downwardly intoengagemerit/with the top of the balls L. The washer 92 is slidablyengaged over the stepped portion of the head 62 and is adapted to bestopped by the shoulder 67.

When the piston G is raised (or retracted) by the return spring 54, thelatching stem 53 enters the bore 64in the anchor head 62. During thisoperation (see Fig. 4) the balls L which normally project somewhat intothe bore 64, are engaged by the chamfer 56 on the latching stem 53 andare lifted, lifting the washer 92 and compressing the spring 91. Whenthe parts reach the position illustrated in Fig. 4 the balls are movedradially outward, at the top of the sleeve Y, through action of thechamfer 56 and top inclined side 69 of the opening 68. Thus, thelatching stem 53 passes the balls L and enters into the bore 64.

When the piston G is held in said raised (or retracted) position by thespring 54, the balls L are yieldingly urged into locking position by thebiasing means and washer 92. That is, the spring biased washer 92 urgesthe balls L inwardly, the balls L being guided by the chamfer 74 on thesleeve Y and by the upper wall of the channel 55 in the latching stem53. When the balls are in the locked position shown in Fig. 5 of thedrawings the balls are held radially inward by the bore 70 in the sleeveY, so that downward force can be applied to the piston G withoutmovement thereof and with the result that the piston G is locked in anup position.

When the piston body 80 of the pressure responsive means Z is lifted byfluid pressure, the sleeve Y is lifted, and when the parts reach theposition shown in Fig. 6, the balls L shift radially outward into therecess 73 in the sleeve Y, thereby rleasing the latching stem 53 andpiston G. The sleeve Y is free to move upwardly relative to the pistonbody 80, a limited distance which action occurs by virtue of the camaction involved when the balls L engaged with the pitched sides of therecess 73. i

From the foregoing it will be apparent that we have provided acommercially practical latch and release for '7 use in connection withfastener driving tools. Each time the valve means I is operated to admitfluid pressure to the cylinder I2, pressure is built up within thecylinder 12 until the pressure responsive means Z is operated to actuatethe release of the piston G. When the valve means I is operated toexhaust fluid from the cylinder 12 the return spring retracts or raisesthe piston G and latching stem 53 so that the head is latched or lockedwith the balls L, all as hereinabove pointed out.

Having described only a typical preferred form and application of ourinvention, we do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to ourselves anyvariations or modifications that may appear to those skilled in the artand fall within the scope of the following claims.

Having described our invention, we claim:

1. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinder,a radially shiftable ball guided by a longitudinal slot-shaped openingformed in the anchor and controlled by a sleeve to latch onto the stem,and a pressure responsive means to shift the sleeve and to therebyrelease the ball both radially and longitudinally from latchingengagement with the stem.

2. A fluid operated tool of the character described including, acylinder, a piston engaged in the. cylinder for operation axiallythereof, there being a latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinder,a radially shiftable ball guided by a longitudinal slot-shaped openingformed in the anchor and controlled by a sleeve to latch onto the stem,said opening being tapered to re strict inward shifting of the ball andhaving a flat bottom for seating engagement with the ball, and apressure responsive means to shift the sleeve and to thereby release theball both radially and longitudinally from the bottom of said openingand from latching engagement with the stem. 3. A fluid operated tool ofthe character described including, a cylinder, a piston engaged in thecylinder for operation axially thereof, there being a latching stemprojecting from the piston, and a releasable latching means comprising,an anchor carried by the cylinder and having a head with a bore adaptedto receive the stem projecting from the piston and with a longitudinalslot-shaped opening entering laterally into said bore, a radially andlongitudinally shiftable ball carried in said opening and guided toproject into said bore and controlled by a sleeve to latch onto thestern projecting from the piston, and a pressure responsive means toshift the sleeve and to thereby release the ball both radially andlongitudinally from latching engagement with the stem projecting fromthe piston.

4. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinderand having a head with a bore adapted to receive the ste projecting fromthe piston and with a longitudinal slotshaped opening entering laterallyinto said bore, a radially and longitudinally shiftable ball carried insaid opening and guided to project into said bore andlatch onto the stemprojecting from the piston, a sleeve surrounding the head and normallyholding the ball inwardly and shiftable to a position allowing the ballsto shift radially outwardly, and a pressure responsive means to shiftthe sleeve and to thereby release the ball from the stem and comprisinga piston surrounding the said head and engaged in the cylinder foroperation axially thereof and coupled to the sleeve to lift the same.

5. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a' latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinderand having'a head with a bore adapted to receive the stem projectingfrom the piston and with a longitudinal slotshaped opening enteringlaterally into said bore, a radially and longitudinally shiftable ballcarried in said opening and guided to project into said bore and latchonto the stem projecting from the piston, a sleeve surrounding the headand with a bore and normally holding the balls radially inwardly andwith a recess shiftable to a position allowing the balls to shiftradially outwardly, and a pressure responsive means to shift the sleeveand thereby to release the ball from the stem and comprising a pistonsurrounding the said head and engaged in the cylinder for operationaxially thereof and with a cylindrical skirt slidably engaged with andcoupled to the sleeve to lift the same.

6. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinderand having a head with a bore adapted to receive the stem projectingfrom the piston and with a longitudinal vertically disposed slot shapedopening in the head and entering the bore therein, a radially shiftableball carried in said opening and guided thereby to shift vertically andradially outwardly when the head is projected into said bore and to thenshift downwardly and radially inwardly to latch onto the stem, and apressure responsive means to release the balls from the stern projectingfrom the piston. 7. A fluid operated tool of the character describedincluding, a cylinder, a piston engaged in the cylinder for operationaxially thereof, there being a latching stem projecting from the piston,and a releasable latching means comprising, an anchor carried by thecylinder and having a head with a bore adapted to receive the stemprojecting from the piston and with a longitudinal vertically disposedslot shaped opening in the head and entering the bore therein, aradially shiftable ball carried in said opening and guided thereby toshift vertically and radially outward when the head is projected intosaid bore and to then shift downwardly and radially inward to latch ontothe stern, a sleeve surrounding the head and normally holding theradially, inwardly and shiftable to a position allowing the ball toshift radially outwardly, and a pressure responsive means to shift thesleeve to release the ball from the stem projecting from the piston.

8. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinderand having a head with a bore adapted to receive the stem projectingfrom the piston and with a longitudinal vertically disposed slot shapedopening in the head and entering the bore therein, a radially shiftableball carried in said opening and guided thereby to shift vertically andradially outward when the head is projected into said bore and to thenshift downwardly and radially inwardly to latch onto the stem, a sleevesurrounding the head and with a bore and normally holding the ballradially inwardly and with a recess shiftable to a position allowing theball to shift radially outwardly, and a pressure responsive means toshift the sleeve to release the ball from the stem projecting from thepiston.

9. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston and withan annular channel shaped recess therein, and a releasable latchingmeans comprising, an anchor carried by the cylinder and having a headwith a bore adapted to receive the stem projecting from the piston andwith a longitudinal vertically disposed slot shaped opening in the headand entering the bore therein, a radially shiftable ball carried in saidopening and guided thereby to shift vertically and radially outward whenthe head is projected into said here and to then shift downwardly andradially inward to latch onto the stem, means yieldingly urging the ballaxially and downwardly, and a pressure responsive means to shift theball and to release it from the stem projecting from the piston.

10. A fluid operated tool of the character described including, acylinder, 2. piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston and withan annular channel shaped recess therein, and a releasable latchingmeans comprising, an anchor carried by the cylinder and having a headwith a bore adapted to receive the stem pro jecting from the piston andwith a longitudinal vertically disposed slot shaped opening in the headand entering the bore therein, a radially shiftable ball carried in saidopening and guided thereby to shift vertically and radially outward whenthe head is projected into said bore and to then shift downwardly andradially inward to latch onto the stem, a sleeve surrounding the headand normally holding the ball radially inwardly and shiftable to a position allowing the ball to shift radially outwardly, means yieldinglyurging the ball axially and downwardly, and a pressure responsive meansto shift the sleeve to release the ball from the stem projecting fromthe piston.

11. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston and withan annular channel shaped recess therein, and a releasable latchingmeans comprising, an anchor carried by the cylinder and having a headwith a bore adapted to receive the stern projecting from the piston andwith a longitudinal vertically disposed slot shaped opening in the headand entering the bore therein, a radially shiftable ball carried in saidopening and guided thereby to shift vertically and radially outward whenthe head is projected into said bore and to then shift downwardly andradially inward to latch onto the stem, a sleeve surrounding the headand with a bore normally engaging and holding if) the ball radiallyinwardly and with a recess and shiftabl to a position allowing the ballto shift radially outwandly, means yieldingly urging the ball axiallyand downwardly, and a pressure responsive means to shift the sleeve torelease the ball from the stem projecting from the piston.

'12. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinder,a radially shiftable ball guided by the anchor and adapted to latch ontothe stem, and a pressure responsive means to the ball to release it fromthe stem, and comprising a piston surrounding the said head and engagedin the cylinder for operation axially thereof and biased to shift whenfluid pressure is developed in the cylinder, the last mentioned pistonbeing coupled to the sleeve to lift the same.

13. A fluid operated tool of the character described including, acylinder, a piston engaged in the cylinder for operation axiallythereof, there being a latching stem projecting from the piston, and areleasable latching means comprising, an anchor carried by the cylinderand having a stem with a head with a bore adapted to receive the stemprojecting from the piston, a radially shiftable ball guided by the headto project into said bore and latch onto the stem projecting from thepiston, and a pressure responsive means to shift the 'ball to release itfrom the stem projecting from the piston and comprising a pistonsurrounding the said head and in slidable sealed engagement with thestem of the anchor and engaged in the cylinder for operation axiallythereof and biased in one direction so as to shift when fluid pressureis developed in the cylinder.

References'Cited in the file of this patent UNITED STATES PATENTS2,290,256 Souter July 21, 1942 2,559,478 Stone July 3, 1951 2,768,610Lieser Oct. 30, 1956 2,774,968 Osborne et al Dec. 25, 1956

